Multilayer coil components

Abstract

To provide a laminate type coil component including a determination mark that can suppress an increase in floating capacitance.SOLUTION: A laminate type coil component 1 includes a multilayer body 10, and a first external electrode 21 and a second external electrode 22 electrically connected to a coil L. The coil L is formed by electrically connecting a plurality of coil conductors 32a to 32d stacked with an insulating layer. The multilayer body 10 includes a first end surface 11 and a second end surface 12 that face each other in a length direction. On a surface excluding the first end surface and the second end surface where the first external electrode is disposed, a first determination mark 50 is provided. The first determination mark 50 includes a first mark conductor pattern that is in contact with an inner surface of the external electrode and has its surface spreading in a direction perpendicular to an axial direction of the coil L. The first mark conductor pattern includes a notch at a position facing a coil shaft A of the coil L.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] The present invention relates to a multilayer coil component. [Background technology]

[0002] Patent Document 1 discloses a multilayer electronic component that is manufactured by processing grooves in a green sheet, printing multiple amounts of conductive paste vertically and horizontally in the grooves, stacking multiple green sheets to form multiple coils inside, cutting and firing, and providing terminal electrodes on both ends, wherein the coil conductor formed from the conductive paste has a cross-sectional shape after firing in which parts of the coil conductor overlap on both sides of the groove, and the aspect ratio t / w of the thickness t to width w of the cross section of the coil conductor is 0.7 or more. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-207608 Summary of the Invention [Problem to be solved by the invention]

[0004] When the axial direction of the coil is parallel to the mounting surface, as in the multilayer electronic component described in Patent Document 1, the stray capacitance generated between the coil and the external electrodes can be reduced.

[0005] In order to further reduce stray capacitance, the inventors considered forming external electrodes only on part of the end faces or side faces of the laminate, thereby reducing the area of ​​the external electrodes facing the coil. However, when attempting to form external electrodes only on part of the end faces or side faces of the laminate, it is not possible to determine the locations where the external electrodes should be formed simply by looking at the top, bottom, side, or end faces of the laminate. This makes it difficult to automate this determination using a sensor or the like.

[0006] Therefore, the inventors decided to provide a mark (discrimination mark) to identify the location where the external electrode should be formed, but found that if the discrimination mark is too small, the mark itself will not be properly exposed on the mounting surface due to misalignment of the laminate block during manufacturing.

[0007] Therefore, we considered simply making the discrimination mark larger, but this would actually increase the stray capacitance.

[0008] The present invention has been made to solve the above problems, and has an object to provide a multilayer coil component having a discrimination mark that is large enough to be exposed even if cutting misalignment occurs, yet can suppress an increase in stray capacitance. [Means for solving the problem]

[0009] A multilayer coil component of the present invention includes: a laminate formed by laminating a plurality of insulating layers and having a coil, a first connecting conductor, and a second connecting conductor therein; and first and second external electrodes electrically connected to the coil, wherein the coil is formed by electrically connecting a plurality of coil conductors laminated together with the insulating layers, and the laminate has a first end face and a second end face opposing each other in a length direction, a first main face and a second main face opposing each other in a height direction perpendicular to the length direction, and a first side face and a second side face opposing each other in a width direction perpendicular to the length direction and the height direction, the first external electrode covers at least a part of the first end face and is disposed so as to extend from the first end face and cover a part of the first main face, and the second external electrode covers at least a part of the second end face, , extending from the second end face and arranged to cover a part of the first main surface, the first connecting conductor connecting the first external electrode in the part covering the first end face to the coil conductor facing thereto, the second connecting conductor connecting the second external electrode in the part covering the second end face to the coil conductor facing thereto, the axial direction of the coil being parallel to the first main surface, a first discrimination mark being provided on a surface of the laminate excluding the first end face and the second end face at a location where the first external electrode is located, the first discrimination mark being in contact with an inner surface of the first external electrode and including a first mark conductor pattern having a surface extending in a direction perpendicular to the axial direction of the coil, and the first mark conductor pattern having a notch provided in a location facing the coil axis of the coil. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a multilayer coil component having a discrimination mark that is large enough to be exposed even if cutting misalignment occurs, yet can suppress an increase in stray capacitance. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view schematically showing a multilayer coil component according to a first embodiment of the present invention. [Figure 2A] FIG. 2A is a side view of the multilayer coil component shown in FIG. [Figure 2B] FIG. 2B is a front view of the multilayer coil component shown in FIG. [Figure 2C] FIG. 2C is a bottom view of the multilayer coil component shown in FIG. [Figure 3] FIG. 3 is an exploded plan view schematically showing an example of a laminate constituting the laminated coil component shown in FIG. [Figure 4A] FIG. 4A is a side view schematically showing, in perspective, an example of the internal structure of the laminate constituting the multilayer coil component according to the first embodiment of the present invention. [Figure 4B] FIG. 4B is a front view schematically showing, in a see-through manner, an example of the internal structure of the laminate constituting the multilayer coil component according to the first embodiment of the present invention. [Figure 4C] FIG. 4C is a bottom view schematically showing an example of the first main surface of the laminate constituting the multilayer coil component according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a perspective front view schematically showing an example of the internal structure of a laminate block constituting a laminated coil component according to a comparative embodiment of the present invention, and shows the positional relationship between the laminate block and cutting lines. [Figure 6] FIG. 6 is a front view corresponding to FIG. 4B, showing the positional relationship between the laminate block and the cutting lines. [Figure 7] FIG. 7 is a perspective front view schematically showing another example of the internal structure of the laminate constituting the multilayer coil component according to the first embodiment of the present invention, illustrating a first modified example of the cutout. [Figure 8] FIG. 8 is a perspective front view schematically showing yet another example of the internal structure of the laminate constituting the multilayer coil component according to the first embodiment of the present invention, illustrating a second modified example of the cutout. [Figure 9] FIG. 9 is a front view schematically showing an example of a step of cutting the laminate block that constitutes the laminated coil component according to the first embodiment of the present invention. [Figure 10]FIG. 10 is an exploded plan view schematically showing an example of a laminate constituting the laminated coil component according to the second embodiment of the present invention. [Figure 11A] FIG. 11A is a perspective side view schematically showing an example of the internal structure of a laminate constituting a multilayer coil component according to a second embodiment of the present invention. [Figure 11B] FIG. 11B is a front view schematically showing, in a see-through manner, an example of the internal structure of the laminate constituting the multilayer coil component according to the second embodiment of the present invention. [Figure 11C] FIG. 11C is a bottom view schematically showing an example of the first main surface of the laminate constituting the multilayer coil component according to the second embodiment of the present invention. [Figure 12] FIG. 12 is a front view showing a schematic perspective view of another example of the internal structure of the laminate constituting the multilayer coil component according to the second embodiment of the present invention, illustrating a first modified example of the cutout. [Figure 13] FIG. 13 is a perspective front view schematically showing yet another example of the internal structure of the laminate constituting the multilayer coil component according to the second embodiment of the present invention, illustrating a second modified example of the cutout. DETAILED DESCRIPTION OF THE INVENTION

[0012] The laminated coil component of the present invention will be described below. However, the present invention is not limited to the following embodiments and can be applied by making appropriate modifications within the scope of the present invention. Note that the present invention also includes a combination of two or more of the individual desirable configurations described below.

[0013] (First embodiment) Fig. 1 is a perspective view schematically showing a laminated coil component according to a first embodiment of the present invention. Fig. 2A is a side view of the laminated coil component shown in Fig. 1. Fig. 2B is a front view of the laminated coil component shown in Fig. 1. Fig. 2C is a bottom view of the laminated coil component shown in Fig. 1.

[0014] The multilayer coil component 1 shown in FIGS. 1, 2A, 2B, and 2C includes a laminate 10, a first external electrode 21, and a second external electrode 22. The laminate 10 has a roughly rectangular parallelepiped shape with six sides. The configuration of the laminate 10 will be described later; it is made by stacking multiple insulating layers and has a coil inside. The first external electrode 21 and the second external electrode 22 are each electrically connected to the coil.

[0015] In the multilayer coil component and laminate of the present invention, the length direction, height direction, and width direction are defined as the x direction, y direction, and z direction in Fig. 1. Here, the length direction (x direction), height direction (y direction), and width direction (z direction) are perpendicular to one another.

[0016] As shown in Figures 1, 2A, 2B, and 2C, the laminate 10 has a first end face 11 and a second end face 12 that face each other in the length direction (x direction), a first main face 13 and a second main face 14 that face each other in the height direction (y direction) perpendicular to the length direction, and a first side face 15 and a second side face 16 that face each other in the width direction (z direction) perpendicular to the length direction and height direction.

[0017] Although not shown in Fig. 1, the corners and ridges of the laminate 10 are preferably rounded. A corner is a portion where three surfaces of the laminate intersect, and a ridge is a portion where two surfaces of the laminate intersect.

[0018] In FIGS. 1 and 2B , the first external electrode 21 is disposed so as to cover a portion of the first end face 11 of the laminate 10, and as shown in FIGS. 1 and 2C , it extends from the first end face 11 to cover a portion of the first main face 13. In FIG. 2B , the first external electrode 21 covers a region of the first end face 11 that includes a ridge line intersecting with the first main face 13, but does not cover a region that includes a ridge line intersecting with the second main face 14. Therefore, the first end face 11 is exposed in the region that includes the ridge line intersecting with the second main face 14. Although not shown in FIGS. 1 and 2B , the first external electrode 21 may be disposed so as to cover the entire first end face 11. In this case, it may cover a ridge line intersecting with the first end face 11 and the second main face 14. Furthermore, the first external electrode 21 may further cover a portion of the second main surface 14, but in this case, the area of ​​the second main surface 14 covered by the first external electrode 21 is smaller than the area of ​​the first main surface 13 covered by the first external electrode 21.

[0019] In FIG. 2B , the height of the first external electrode 21 in the portion covering the first end face 11 of the laminate 10 is constant, but the shape of the first external electrode 21 is not particularly limited. For example, on the first end face 11 of the laminate 10, the first external electrode 21 may have an arched shape that becomes higher from the end toward the center. In FIG. 2C , the length of the first external electrode 21 in the portion covering the first main surface 13 of the laminate 10 is constant, but the shape of the first external electrode 21 is not particularly limited. For example, on the first main surface 13 of the laminate 10, the first external electrode 21 may have an arched shape that becomes longer from the end toward the center.

[0020] As shown in FIGS. 1 and 2A , the first external electrode 21 may be arranged so as to extend from the first end face 11 and the first main surface 13 and cover a portion of the first side face 15 and a portion of the second side face 16. In this case, as shown in FIG. 2A , the portions of the first external electrode 21 covering the first side face 15 and the second side face 16 may both be formed obliquely with respect to the ridge line intersecting with the first end face 11 and the ridge line intersecting with the first main surface 13. Note that the first external electrode 21 does not have to be arranged so as to cover a portion of the first side face 15 and a portion of the second side face 16. In FIGS. 1 and 2A , the shape of the first external electrode 21 covering the first side face 15 of the laminate 10 is a right-angled triangle, but the shape of the first external electrode 21 is not particularly limited. For example, on the first side surface 15 of the laminate 10, the boundary line of the first external electrode 21 that extends from the first end face 11 to the first main surface 13 may be curved. In FIG. 1 , the shape of the first external electrode 21 in the portion covering the second side surface 16 of the laminate 10 is a right triangle, but the shape of the first external electrode 21 is not particularly limited. For example, on the second side surface 16 of the laminate 10, the boundary line of the first external electrode 21 that extends from the first end face 11 to the first main surface 13 may be curved.

[0021] The second external electrode 22 is disposed so as to cover a portion of the second end face 12 of the laminate 10 and extend from the second end face 12 to cover a portion of the first main face 13. Like the first external electrode 21, the second external electrode 22 covers a region of the second end face 12 that includes a ridge line that intersects with the first main face 13, but does not cover a region that includes a ridge line that intersects with the second main face 14. Therefore, the second end face 12 is exposed in the region that includes the ridge line that intersects with the second main face 14. Although not shown in the figure, the second external electrode 22 may be disposed so as to cover the entire second end face 12. In this case, the ridge line that intersects with the second end face 12 and the second main face 14 may be covered. Furthermore, the second external electrode 22 may further cover a portion of the second main surface 14, but in this case, the area of ​​the second main surface 14 covered by the second external electrode 22 is smaller than the area of ​​the first main surface 13 covered by the second external electrode 22.

[0022] As with the first external electrode 21, the shape of the second external electrode 22 is not particularly limited. For example, on the second end surface 12 of the laminate 10, the second external electrode 22 may have an arched shape that becomes higher from the end toward the center. Furthermore, the shape of the second external electrode 22 is not particularly limited. For example, on the first main surface 13 of the laminate 10, the second external electrode 22 may have an arched shape that becomes longer from the end toward the center.

[0023] Similar to the first external electrode 21, the second external electrode 22 may be arranged so as to extend from the second end face 12 and the first main surface 13 and cover a portion of the first side face 15 and a portion of the second side face 16. In this case, the portions of the second external electrode 22 covering the first side face 15 and the second side face 16 may both be formed obliquely with respect to the ridge line intersecting with the second end face 12 and the ridge line intersecting with the first main surface 13. Note that the second external electrode 22 does not have to be arranged so as to cover a portion of the first side face 15 and a portion of the second side face 16. Similar to the first external electrode 21, the shape of the portion of the second external electrode 22 covering the first side face 15 of the laminate 10 is not particularly limited. For example, on the first side face 15 of the laminate 10, the boundary line of the second external electrode 22 spanning from the second end face 12 to the first main surface 13 may be curved. Furthermore, there are no particular limitations on the shape of the second external electrode 22 in the portion covering the second side surface 16 of the laminate 10. For example, on the second side surface 16 of the laminate 10, the boundary line of the second external electrode 22 that spans from the second end face 12 to the first main surface 13 may be curved.

[0024] Since the first external electrodes 21 and the second external electrodes 22 are arranged as described above, when the laminated coil component 1 is mounted on a substrate, the first main surface 13 of the laminate 10, which has the largest sum of the areas where the first external electrodes and the second external electrodes are formed, becomes the mounting surface.

[0025] The size of the multilayer coil component of the present invention is not particularly limited, but is preferably 0603 size or 0402 size.

[0026] When the laminated coil component of the present invention is 0603 size, the length of the laminated coil component (the length indicated by the double-headed arrow L in FIG. 2A ) including the dimensions of the first external electrode and the second external electrode is preferably 0.57 mm or more and 0.63 mm or less, and the width of the laminated coil component (the length indicated by the double-headed arrow W in FIG. 2C ) is preferably 0.27 mm or more and 0.33 mm or less.

[0027] When the laminated coil component of the present invention is 0603 size, the height of the laminated coil component (the length indicated by the double-headed arrow T in FIG. 2B ), including the dimensions of the first external electrode and the second external electrode, is preferably 0.27 mm or more and 0.33 mm or less.

[0028] When the external electrodes cover only a portion of the end faces, the height of the first external electrode covering the first end face of the laminate may be 3 / 10 to 3 / 4, or 1 / 3 to 2 / 3, of the height of the first end face. Similarly, the height of the second external electrode covering the second end face of the laminate may be 3 / 10 to 3 / 4, or 1 / 3 to 2 / 3, of the height of the second end face. When the heights of the first and second external electrodes are 3 / 10 or more of the heights of the first and second end faces, respectively, the adhesive strength between the solder and the first end face 11 and the second end face 12 can be relatively strong when the solder is mounted on a board by soldering. Furthermore, when the heights of the first and second external electrodes are 1 / 3 or more of the heights of the first and second end faces, respectively, the adhesive strength between the solder and the first end face 11 and the second end face 12 can be further strengthened. When the height of the first external electrode and the height of the second external electrode are ¾ or less of the height of the first end face and the height of the second end face, respectively, the stray capacitance caused by the external electrodes can be relatively reduced. Furthermore, when the height of the first external electrode and the height of the second external electrode are ⅔ or less of the height of the first end face and the height of the second end face, respectively, the stray capacitance caused by the external electrodes can be further reduced.

[0029] When the laminated coil component of the present invention is 0603 size, the length of the portion of the first external electrode covering the first main surface of the laminate (the length indicated by the double arrow E1 in FIG. 2C ) is preferably 0.12 mm or more and 0.22 mm or less. Similarly, the length of the portion of the second external electrode covering the first main surface of the laminate is preferably 0.12 mm or more and 0.22 mm or less. Here, the length of the portion of the first external electrode covering the first main surface of the laminate and the length of the portion of the second external electrode covering the first main surface of the laminate can be determined by measuring the maximum length in the longitudinal direction (x direction) (i.e., the length including the portion outside the laminate) with the first main surface of the laminate viewed in plan. In addition, if the length of the portion of the first external electrode covering the first main surface of the laminate and the length of the portion of the second external electrode covering the first main surface of the laminate are not constant, it is preferable that the length of the longest portion be within the above range.

[0030] When the laminated coil component of the present invention is 0603 size, the height of the first external electrode (the length indicated by the double-headed arrow E2 in FIG. 2B ) in the portion covering the first end face of the laminate is preferably 0.1 mm or more and 0.2 mm or less. Similarly, the height of the second external electrode (the portion covering the second end face of the laminate) is preferably 0.1 mm or more and 0.2 mm or less. Here, the height of the first external electrode (the portion covering the first end face of the laminate) and the height of the second external electrode (the portion covering the second end face of the laminate) can be determined by measuring the maximum length in the height direction (y direction) (i.e., the length including the portion outside the laminate) when the first end face and the second end face of the laminate are viewed in plan. In addition, if the height of the first external electrode covering the first end face of the laminate and the height of the second external electrode covering the second end face of the laminate are not constant, it is preferable that the height of the highest part be within the above range.

[0031] When the laminated coil component of the present invention is 0402 size, the length of the laminated coil component, including the dimensions of the first external electrodes and the second external electrodes, is preferably 0.38 mm or more and 0.42 mm or less, and the width of the laminated coil component is preferably 0.18 mm or more and 0.22 mm or less.

[0032] When the laminated coil component of the present invention is 0402 size, the height of the laminated coil component, including the dimensions of the first external electrodes and second external electrodes, is preferably 0.18 mm or more and 0.22 mm or less.

[0033] When the laminated coil component of the present invention is 0402 size, the length of the first external electrode covering the first main surface of the laminate is preferably 0.08 mm or more and 0.15 mm or less.Similarly, the length of the second external electrode covering the first main surface of the laminate is preferably 0.08 mm or more and 0.15 mm or less.

[0034] When the laminated coil component of the present invention is 0402 size, the height of the first external electrode covering the first end face of the laminate is preferably 0.06 mm or more and 0.13 mm or less.Similarly, the height of the second external electrode covering the second end face of the laminate is preferably 0.06 mm or more and 0.13 mm or less.

[0035] FIG. 3 is an exploded plan view schematically showing an example of a laminate constituting the laminated coil component shown in FIG.

[0036] As shown in FIG. 3, the laminate 10 is configured by stacking a plurality of insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in the length direction (x direction). The direction in which the insulating layers constituting the laminate are stacked is referred to as the stacking direction.

[0037] The insulating layers 31a, 31b, 31c, and 31d are provided with coil conductors 32a, 32b, 32c, and 32d, and via conductors 33a, 33b, 33c, and 33d, respectively. Note that lands 35a, 35b, 35c, and 35d are included in the coil conductors 32a, 32b, 32c, or 32d. The insulating layer 31e is provided with a via conductor 33e. The insulating layer 31f is provided with a via conductor 33f, a land 35f, and a mark conductor pattern 34.

[0038] Coil conductors 32a, 32b, 32c, and 32d are provided on the main surfaces of insulating layers 31a, 31b, 31c, and 31d, respectively, and are stacked together with insulating layers 31a, 31b, 31c, 31d, 31e, and 31f. In Fig. 3, each coil conductor has a 3 / 4 turn shape, and four insulating layers arranged in this order, 31a, 31b, 31c, and 31d, form one unit (three turns), which are repeatedly stacked. Furthermore, lands 35a, 35b, 35c, and 35d are provided at both ends of each coil conductor 32a, 32b, 32c, and 32d, respectively.

[0039] The via conductors 33a, 33b, 33c, 33d, 33e, and 33f are provided to penetrate the insulating layers 31a, 31b, 31c, 31d, 31e, and 31f in the thickness direction (x direction), respectively.

[0040] A land 35f is provided directly above the via conductor 33f. The lands 35a, 35b, 35c, 35d, and 35f are preferably slightly larger in width than the coil conductors 32a, 32b, 32c, and 32d excluding the lands 35a, 35b, 35c, and 35d.

[0041] The conductive pattern for mark 34 is provided on the main surface of the insulating layer 31f. In Fig. 3, the conductive pattern for mark 34 is provided in two places on the main surface of the insulating layer 31f, both of which are in contact with the outer periphery of the insulating layer 31f.

[0042] The insulating layers 31a, 31b, 31c, 31d, 31e, and 31f configured as described above are stacked in the x direction. As a result, the coil conductors 32a, 32b, 32c, and 32d are electrically connected via the via conductors 33a, 33b, 33c, and 33d. As a result, a solenoid coil having a coil axis parallel to the x direction is formed in the laminate 10.

[0043] Furthermore, the via conductor 33e, together with the via conductor 33f and the land 35f, forms a connecting conductor within the laminate 10 and is exposed at both end surfaces of the laminate 10. That is, the connecting conductor includes the via conductor 33e, the via conductor 33f, and the land 35f. As will be described later, within the laminate 10, the connecting conductor serves as a first connecting conductor that connects the first external electrode 21 and the opposing coil conductor 32a, or a second connecting conductor that connects the second external electrode 22 and the opposing coil conductor 32d.

[0044] The mark conductor pattern 34 is planar and extends in a direction perpendicular to the axial direction of the coil, and is exposed on the first main surface 13 of the laminate 10 to serve as a discrimination mark. For convenience, in this disclosure, it may be said that the discrimination mark has a feature in relation to a feature possessed by at least one mark conductor pattern 34. For example, if the mark conductor pattern constituting the discrimination mark has a notch, it may be said that the discrimination mark has a notch.

[0045] Fig. 4A is a side view showing, in perspective, an example of the internal structure of a laminate constituting the multilayer coil component according to the first embodiment of the present invention. Fig. 4B is a front view showing, in perspective, an example of the internal structure of a laminate constituting the multilayer coil component according to the first embodiment of the present invention. Fig. 4C is a bottom view showing, in perspective, an example of a first main surface of the laminate constituting the multilayer coil component according to the first embodiment of the present invention. Fig. 4B shows a plan view of the laminate in the axial direction of the coil from the first external electrode side (or the second external electrode side).

[0046] As shown in FIG. 4A, in the laminated coil component 1, the lamination direction of the laminate 10 and the axial direction of the coil L (in FIG. 4A, the coil axis A of the coil L is shown) are parallel to the first main surface 13, which is the mounting surface.

[0047] The first connecting conductor 41 linearly connects the portion of the first external electrode 21 covering the first end face 11 to the opposing coil conductor 32a within the laminate 10. Similarly, the second connecting conductor 42 linearly connects the portion of the second external electrode 22 covering the second end face 12 to the opposing coil conductor 32d within the laminate 10. By connecting the coil to the external electrode in a straight line, the lead-out portion can be simplified and high frequency characteristics can be improved.

[0048] When viewed in a plane from the stacking direction (i.e., when viewed in a plane from the axial direction of the coil), it is preferable that the via conductors that make up the connecting conductor overlap each other, but the via conductors that make up the connecting conductor do not have to be aligned in a strictly straight line.

[0049] As shown in Fig. 4B, the first connecting conductor 41 overlaps with the coil conductors that make up the coil L when viewed in a plan view from the stacking direction, and as shown in Fig. 4A, it is located closer to the first main surface 13 (mounting surface) than the coil axis A of the coil L. Similarly, the second connecting conductor 42 overlaps with the coil conductors that make up the coil L when viewed in a plan view from the stacking direction, and it is located closer to the first main surface 13 (mounting surface) than the coil axis A of the coil L.

[0050] 4A and 4B, the first connecting conductor 41 and the second connecting conductor 42 are both provided at positions closest to the first main surface 13 among positions overlapping with the coil conductors that constitute the coil L when viewed from above in the stacking direction. However, the first connecting conductor 41 may be provided at any position as long as it overlaps with the coil conductors that constitute the coil L when viewed from above in the stacking direction and is connected to the first external electrode 21. Similarly, the second connecting conductor 42 may be provided at any position as long as it overlaps with the coil conductors that constitute the coil L when viewed from above in the stacking direction and is connected to the second external electrode 22. Furthermore, although the first connecting conductor 41 and the second connecting conductor 42 overlap with each other when viewed from above in the stacking direction in FIG. 4A, the first connecting conductor 41 and the second connecting conductor 42 do not have to overlap.

[0051] As shown in Fig. 4B, when viewed from above in the stacking direction, the coil conductors constituting the coil L preferably overlap each other. When viewed from above in the stacking direction, the shape of the coil L is preferably circular. Note that the coil L includes lands, but in this case, the shape of the coil L is defined as the shape excluding the lands.

[0052] The discrimination marks 50 are provided on the surface of the laminate 10 excluding the first end face 11 and the second end face 12, at locations where the first external electrode 21 or the second external electrode 22 is to be disposed. In FIGS. 4A and 4C , the discrimination marks 50 are provided on the first main surface 13 of the laminate 10. Although not shown, the location of the discrimination marks 50 is not limited to the first main surface 13, as long as it is a location where the first external electrode 21 or the second external electrode 22 is to be disposed. For example, the discrimination marks 50 may be provided on the first side surface 15, the second side surface 16, or the second main surface 14. The discrimination marks 50 provided at the locations where the first external electrodes 21 are disposed are referred to as first discrimination marks, and the discrimination marks 50 provided at the locations where the second external electrodes 22 are disposed are referred to as second discrimination marks. By providing a discrimination mark on the surface of the laminate, it is possible to easily determine the locations where external electrodes should be formed, which makes it possible to automate the discrimination using a sensor or the like.

[0053] The discrimination mark is composed of a marking conductor pattern provided on at least one insulating layer so as to be exposed on the first principal surface. In other words, the discrimination mark extends from the inside of the laminate and is exposed on the surface of the laminate other than the end face. Furthermore, because the discrimination mark is composed of a marking conductor pattern provided on the insulating layer, the discrimination mark can be easily formed. By providing a conductor pattern so as to contact the outer periphery of the insulating layer, that portion can be exposed from the first principal surface of the laminate 10. However, "exposed" here refers only to being exposed on the surface of the laminate 10. For example, the first discrimination mark and the second discrimination mark are covered by the formation of the first external electrode and the second external electrode, respectively, but are still exposed on the surface of the laminate 10. Therefore, a portion of the first marking conductor pattern for the first discrimination mark contacts the inner surface of the first external electrode 21. Furthermore, a portion of the second marking conductor pattern for the second discrimination mark contacts the inner surface of the second external electrode 22.

[0054] 4C, the discrimination marks 50 are provided on three insulating layers (see insulating layer 31f in FIG. 3) overlapping the first external electrode 21 and on three insulating layers (see insulating layer 31f in FIG. 3) overlapping the second external electrode 22. The discrimination marks 50 are exposed on the first main surface 13 of the laminate 10 and electrically connected to the first external electrode 21 or the second external electrode 22, respectively.

[0055] The discrimination mark may be provided on only one insulating layer, but is preferably provided on at least two insulating layers. The first discrimination mark may include only one first mark conductive pattern, but is preferably provided with two or more spaced apart first mark conductive patterns. Similarly, the second discrimination mark may include only one second mark conductive pattern, but is preferably provided with two or more spaced apart second mark conductive patterns.

[0056] Although the discrimination mark may be provided only at the location where either the first external electrode or the second external electrode is arranged, it is preferable to provide it at the location where the first external electrode and the second external electrode are arranged, respectively. That is, it is preferable to provide a first discrimination mark and a second discrimination mark. In this case, the number of first mark conductor patterns constituting the first discrimination mark provided at the location where the first external electrode is arranged and the number of second mark conductor patterns constituting the second discrimination mark provided at the location where the second external electrode is arranged may be the same or different.

[0057] In this way, it is preferable that the discrimination mark is provided on at least one insulating layer in contact with the first external electrode and on at least one insulating layer in contact with the second external electrode.

[0058] As shown in Fig. 4B, the discrimination mark 50 has a notch 51 at a location facing the coil axis A of the coil L when viewed from above in the axial direction of the coil L. Therefore, even if the discrimination mark 50 is made larger (longer in the height direction), it is possible to prevent an increase in stray capacitance between the external electrode electrically connected to the discrimination mark 50 and the coil or the connecting conductor (particularly the via conductors and lands on the same layer as the discrimination mark 50 in the case shown in Fig. 4B). Furthermore, the size (height dimension) of the discrimination mark 50 can be set to a size that allows it to be exposed on the first main surface 13 of the laminate 10 even if cutting misalignment occurs in the laminate block.

[0059] In this way, the discrimination mark has a missing portion facing the conductor (first connecting conductor 41 and second connecting conductor 42 in Figures 4A and 4B) to ensure a distance from the conductor formed on the same insulating layer.

[0060] FIG. 5 is a perspective front view schematically showing an example of the internal structure of a laminate block constituting a laminated coil component according to a comparative embodiment of the present invention, and shows the positional relationship between the laminate block and cutting lines.

[0061] As shown in FIG. 5 , in the multilayer coil component according to the comparative example, when viewed from above in the axial direction of the coil L, the discrimination mark 50 has a rectangular shape. Therefore, if cutting misalignment occurs and the cutting line (see the dashed-dotted lines in FIG. 5 ) shifts, the discrimination mark 50 may not be properly exposed in the cross section (see the dashed-dotted line X in FIG. 5 ). In this case, the discrimination mark 50 appears faded on the surface of the laminate 10. As a result, the discrimination mark 50 does not fully exhibit its effectiveness, i.e., it may be difficult to identify the locations where external electrodes should be formed. On the other hand, although not shown in the figure, if the rectangular discrimination mark 50 is enlarged in the height direction (y direction) of the laminate 10 to address cutting misalignment, the stray capacitance generated between the coil L and the discrimination mark 50 increases, resulting in a problem of reduced high-frequency characteristics of the coil.

[0062] FIG. 6 is a front view corresponding to FIG. 4B, showing the positional relationship between the laminate block and the cutting lines.

[0063] In contrast, in this embodiment, as shown in Fig. 6, the discrimination mark 50 has a notch 51 provided at a location facing the coil axis A of the coil L, so that the stray capacitance generated between the coil L and the discrimination mark 50 can be suppressed while being increased in the height direction (y direction) of the laminate 10. Therefore, even if cutting misalignment occurs and the cutting lines (see the dashed-dotted lines in Fig. 6) are displaced, the discrimination mark 50 is reliably exposed on the cross section (see the dashed-dotted line X in Fig. 6). Therefore, the discrimination mark 50 can be clearly seen on the surface of the laminate 10, and as a result, the locations where external electrodes should be formed can be reliably identified.

[0064] At least one discrimination mark is preferably provided on an insulating layer on which the first connecting conductor or the second connecting conductor is formed. The first discrimination mark preferably includes a first mark conductor pattern formed on a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the first connecting conductor is formed. That is, both the first connecting conductor and the first mark conductor pattern are preferably exposed on a cross section of the laminate 10 perpendicular to the coil axis A of the coil L. Similarly, the second discrimination mark preferably includes a second mark conductor pattern formed on a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the second connecting conductor is formed. As shown in FIG. 4A , the discrimination mark 50 is more preferably provided on the insulating layer on which the first connecting conductor 41 is formed (see insulating layer 31f in FIG. 3 ) and on the insulating layer on which the second connecting conductor 42 is formed (see insulating layer 31f in FIG. 3 ).

[0065] 7 is a perspective front view schematically showing another example of the internal structure of the laminate constituting the multilayer coil component according to the first embodiment of the present invention, illustrating a first modified example of the cutout. Fig. 7 shows the laminate as viewed from the first external electrode side (or the second external electrode side) in the axial direction of the coil.

[0066] 4B and 7, the discrimination mark 50 may have a linear cutout 51. This makes it possible to effectively increase the size of the discrimination mark 50 (lengthen in the height direction) while suppressing an increase in stray capacitance. The discrimination mark 50 may have a pentagonal shape as shown in FIG. 4B, or a quadrangular shape (e.g., a trapezoidal shape) as shown in FIG.

[0067] 8 is a perspective front view schematically showing yet another example of the internal structure of the laminate constituting the multilayer coil component according to the first embodiment of the present invention, illustrating a second modified example of the cutout. Fig. 8 shows the laminate as viewed from the first external electrode side (or the second external electrode side) in the axial direction of the coil.

[0068] As shown in FIG. 8 , the discrimination mark 50 may have a shape in which the notch 51 follows the outer periphery of the first connecting conductor 41 (preferably, the land 35f closest to the discrimination mark 50) when the laminate 10 is viewed in plan in the axial direction of the coil L. Similarly, the discrimination mark 50 may have a shape in which the notch 51 follows the outer periphery of the second connecting conductor 42 (preferably, the land 35f closest to the discrimination mark 50) when the laminate 10 is viewed in plan in the axial direction of the coil L. This also makes it possible to effectively increase the size of the discrimination mark 50 (lengthen in the height direction) while suppressing an increase in stray capacitance. In this case, the notch 51 may have a curved shape, such as an arc shape.

[0069] In addition, when the discrimination mark is made up of multiple mark conductive patterns, the multiple notches provided in those mark conductive patterns may all have the same shape, or the multiple mark conductive patterns may include notches of different shapes.

[0070] 4B, 7, and 8, the discrimination marks 50 are preferably provided at two separate locations symmetrically about an axis AA perpendicular to the first main surface 13 when viewed in a plan view from the axial direction of the coil L. This doubles the number of discrimination marks 50, thereby more reliably achieving the effect of the discrimination marks 50. The axis AA passes through the coil axis A of the coil L.

[0071] 4B, 7, and 8, when the discrimination mark is provided at a position shifted from the axis AA perpendicular to the first main surface 13, T1 is the dimension of the discrimination mark in the height direction of the laminate, and T2 is the dimension of the discrimination mark farther from the axis AA. T1 is larger than T2. ​​When the multilayer coil component is viewed in plan from the axial direction of the coil L with the second main surface 14 facing up and the first main surface 13 facing down, T1 corresponds to the distance from the first main surface 13 to the highest position of the conductor pattern for mark. When the multilayer coil component is viewed in plan from the axial direction of the coil L with the second main surface 14 facing up and the first main surface 13 facing down, T2 corresponds to the distance from the first main surface 13 to the lowest position of the notch 51 of the conductor pattern for mark. 4B, 7, and 8, when the multilayer coil component is viewed from above in the axial direction of the coil L with the second main surface 14 facing up and the first main surface 13 facing down, T1 may be greater than the distance (shortest distance) from the first main surface 13 of the coil L and the distance (shortest distance) of the first connecting conductor 41 or the second connecting conductor 42 from the first main surface 13, and T2 may be smaller than the distance (shortest distance) from the first main surface 13 of the coil L and the distance (shortest distance) of the first connecting conductor 41 or the second connecting conductor 42 from the first main surface 13. T1 may be, for example, 10 μm or less as a dimension after firing. The shortest distance B between the coil L and the discrimination mark and the shortest distance C between the first connecting conductor 41 or the second connecting conductor 42 and the discrimination mark may both be 5 μm or more, or may be 10 μm or more. If the shortest distance B between the coil L and the discrimination mark is 5 μm or more, the increase in stray capacitance can be suppressed, resulting in good high-frequency characteristics. If the shortest distance B is 10 μm or more, the increase in stray capacitance can be further suppressed, resulting in even better high-frequency characteristics. Here, the shortest distances B and C are measured by measuring the distance between the closest points of the coil or connecting conductor and the discrimination mark when viewing a cross section of the multilayer coil component perpendicular to the lamination direction.

[0072] In the example shown in Fig. 4C, three discrimination marks 50 are provided in each of four regions that include each corner of the first main surface 13. Note that one or two discrimination marks may be provided in each of the four regions, or four or more discrimination marks may be provided in each of the four regions. When discrimination marks are provided in multiple regions, the number of discrimination marks included in each region may be the same or different.

[0073] The width of the line constituting the discrimination mark (the dimension in the width direction of the laminate) is not particularly limited, but is preferably 0.04 mm or more and 0.1 mm or less. The thickness (the dimension in the length direction of the laminate) and shape of the line are also not particularly limited.

[0074] An example of a method for manufacturing the multilayer coil component according to the first embodiment of the present invention will now be described.

[0075] First, a ceramic green sheet that will become an insulating layer is prepared. For example, an organic binder such as polyvinyl butyral resin, an organic solvent such as ethanol or toluene, and a dispersant are added to the ferrite raw material and kneaded to form a slurry. Then, a magnetic sheet with a thickness of about 12 μm is obtained by a method such as a doctor blade method.

[0076] As a ferrite raw material, for example, oxide raw materials of iron, nickel, zinc, and copper can be mixed and calcined at 800°C for 1 hour, then pulverized in a ball mill and dried to obtain a Ni-Zn-Cu ferrite raw material (oxide mixed powder) with an average particle size of approximately 2 μm.

[0077] The ceramic green sheets that form the insulating layers can be made of, for example, magnetic materials such as ferrite materials, non-magnetic materials such as glass ceramic materials, or mixtures of these magnetic and non-magnetic materials. When producing ceramic green sheets using ferrite materials, in order to obtain a high L value (inductance), it is preferable to use a ferrite material with a composition of Fe2O3: 40 mol% to 49.5 mol%, ZnO: 5 mol% to 35 mol%, CuO: 4 mol% to 12 mol%, and the remainder: NiO and trace amounts of additives (including unavoidable impurities).

[0078] The produced ceramic green sheets are subjected to a specified laser processing to form via holes with a diameter of approximately 20 μm or more and 30 μm or less. The via holes are filled with Ag paste on a specific sheet with via holes, and a conductor pattern (coil conductor) with a thickness of approximately 11 μm and a 3 / 4 turn shape for surrounding the coil is screen-printed and dried to obtain a coil sheet. Furthermore, coil sheets with only via conductors that form part of the connecting conductor and coil sheets with only via conductors and land portions are also obtained in the same way. These coil sheets without printed coil conductors are sometimes referred to as via sheets.

[0079] The coil sheets are stacked so that after cutting, a coil having a coil axis parallel to the mounting surface is formed inside the laminate. Furthermore, via sheets having via conductors that serve as connecting conductors are stacked on top of each other. At least one of the via sheets is a marked via sheet having a conductor pattern for a mark formed thereon.

[0080] FIG. 9 is a front view schematically showing an example of a step of cutting the laminate block that constitutes the laminated coil component according to the first embodiment of the present invention.

[0081] The stacked coil sheet and via sheet are thermocompressed to obtain a laminate block approximately 0.67 mm thick. As shown in FIG. 9, this is then cut along the cutting lines (dotted lines in FIG. 9) to obtain individual chips with chip dimensions of 0.67 mm in length, 0.34 mm in width, and 0.34 mm in height. Even if the cutting misalignment occurs and the cutting line shifts (see, for example, the dashed line X in FIG. 9), the discriminant mark 50 has a notch 51, so that even chips cut smaller than the standard (for example, the top two in FIG. 9) still have the discriminant mark 50 clearly visible on the cross section. The individual chips may be subjected to a rotary barrel to round the corners and ridges as desired.

[0082] The binder is removed and the material is fired at a predetermined temperature for a predetermined time to obtain a fired body (laminate) with a coil built in.

[0083] The chip is dipped at an angle into a layer of Ag paste stretched to a specified thickness and baked to form base electrodes for the external electrodes on the four surfaces (main surface, end surfaces, and both side surfaces) of the laminate. In the above method, the base electrode can be formed in one step, compared to when the base electrode is formed twice, once on the main surface and once on the end surface of the laminate.

[0084] An Ni film and an Sn film having a predetermined thickness are sequentially formed on the base electrode by plating to form an external electrode.

[0085] Another method for forming the external electrodes is to dip a brush into Ag paste and apply the paste to the areas where the external electrodes are to be formed. This method allows for easier manipulation of the shape of the external electrodes than methods for forming external electrodes by immersing the laminate in Ag paste. For example, it is possible to form external electrodes that cover the end faces and parts of the main surfaces but not both side surfaces. In this manner, the multilayer coil component according to the first embodiment of the present invention can be fabricated.

[0086] (Second embodiment) This embodiment differs from the first embodiment in that a discrimination mark is also provided on the insulating layer on which the coil conductor is formed. Therefore, like the multilayer coil component of the first embodiment, the multilayer coil component of this embodiment includes a laminate, first external electrodes, and second external electrodes, as shown in Figures 1, 2A, 2B, and 2C.

[0087] FIG. 10 is an exploded plan view schematically showing an example of a laminate constituting the laminated coil component according to the second embodiment of the present invention.

[0088] As shown in FIG. 10, the laminate 10A included in the laminated coil component 1A of this embodiment is configured by stacking multiple insulating layers 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, 31j, and 31k in the length direction (x direction).

[0089] The insulating layers 31a, 31b, 31c, 31d, 31e, and 31f are as described in the first embodiment. The insulating layers 31g, 31h, 31j, and 31k are provided with coil conductors 32a, 32b, 32c, and 32d, via conductors 33a, 33b, 33c, and 33d, and a mark conductor pattern 34, respectively. The insulating layers 31g, 31h, 31j, and 31k are provided on their main surfaces with lands 35a, 35b, 35c, and 35d connected to the via conductors 33a, 33b, 33c, and 33d, respectively. The lands 35a, 35b, 35c, and 35d are included in the coil conductors 32a, 32b, 32c, or 32d.

[0090] In this embodiment, each coil conductor also has a 3 / 4 turn shape, but four insulating layers 31c, 31d, 31a, and 31b arranged in this order are stacked repeatedly as one unit (three turns).

[0091] The conductive pattern for mark 34 is provided on the main surfaces of the insulating layers 31g, 31h, 31j, and 31k in addition to the insulating layer 31f. In Fig. 10, the conductive pattern for mark 34 is provided in two places on the main surfaces of the insulating layers, both of which are in contact with the outer periphery of the insulating layers.

[0092] The insulating layers 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, 31j, and 31k configured as described above are stacked in the x direction. As a result, the coil conductors 32a, 32b, 32c, and 32d are electrically connected via the via conductors 33a, 33b, 33c, and 33d. As a result, a solenoid coil having a coil axis parallel to the x direction is formed in the laminate 10A.

[0093] Furthermore, the via conductor 33e, together with the via conductor 33f and the land 35f, forms a connecting conductor within the laminate 10A and is exposed at both end surfaces of the laminate 10A. That is, the connecting conductor includes the via conductor 33e, the via conductor 33f, and the land 35f. Within the laminate 10A, the connecting conductor serves as a first connecting conductor that connects the first external electrode 21 and the opposing coil conductor 32a, or a second connecting conductor that connects the second external electrode 22 and the opposing coil conductor 32d.

[0094] The mark conductor pattern 34 is planar and extends in a direction perpendicular to the axial direction of the coil, and is exposed on the first main surface 13 of the laminate 10A to serve as a discrimination mark.

[0095] In this embodiment, the mark conductor pattern 34 is provided not only on the insulating layer 31f on which the via conductor 33f for the connecting conductor is provided, but also on the insulating layers 31g, 31h, 31j and 31k on which the coil conductors 32a, 32b, 32c and 32d are provided.

[0096] In this manner, at least one discrimination mark may be provided on an insulating layer on which a coil conductor is formed. In this case, the discrimination mark is preferably provided on an insulating layer on which a coil conductor located at one end or the other end (outermost) of the multiple coil conductors is formed, and more preferably provided on each insulating layer on which a coil conductor located at one end and the other end (outermost) is formed. Furthermore, the first discrimination mark preferably includes a first mark conductor pattern formed in a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the coil conductor (preferably the coil conductor located at one end or the other end (outermost)) is formed. That is, it is preferable that both the coil conductor (preferably the coil conductor located at one end or the other end (outermost)) and the first mark conductor pattern are exposed in a cross section of the laminate 10 perpendicular to the coil axis A of the coil L. Similarly, the second discrimination mark preferably includes a second mark conductor pattern formed in a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the coil conductor (preferably the coil conductor located at one end or the other end (outermost)) is formed.

[0097] Alternatively, at least one discrimination mark may be provided on an insulating layer on which the first connecting conductor or the second connecting conductor is formed, and the remaining discrimination marks may be provided on insulating layers on which the coil conductors are formed. That is, the discrimination marks may be provided only on the insulating layer on which the first connecting conductor or the second connecting conductor is formed, or on the insulating layer on which the coil conductors are formed. Preferably, the first discrimination mark includes a first mark conductor pattern formed in a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the first connecting conductor is formed, and a first mark conductor pattern formed in a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the coil conductor is formed. Similarly, it is preferable that the second discrimination mark includes a second mark conductor pattern formed in a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the second connecting conductor is formed, and a second mark conductor pattern formed in a cross section of the laminate 10 perpendicular to the coil axis A of the coil L, where the coil conductor is formed.

[0098] Fig. 11A is a side view showing, in perspective, an example of the internal structure of a laminate constituting the laminate coil component according to the second embodiment of the present invention. Fig. 11B is a front view showing, in perspective, an example of the internal structure of a laminate constituting the laminate coil component according to the second embodiment of the present invention. Fig. 11C is a bottom view showing, in perspective, an example of a first main surface of a laminate constituting the laminate coil component according to the second embodiment of the present invention. Fig. 11B shows a plan view of the laminate in the axial direction of the coil from the first external electrode side (or the second external electrode side).

[0099] As shown in FIGS. 11A and 11C, in this embodiment as well, the discrimination mark 50 is provided on the first main surface 13 of the laminate 10A.

[0100] 11B, similar to the first embodiment, the discrimination mark 50 has a notch 51 at a location facing the coil axis A of the coil L when viewed in a plan view from the axial direction of the coil L. Therefore, even if the discrimination mark 50 is made larger (longer in the height direction), it is possible to prevent an increase in stray capacitance between the external electrode electrically connected to the discrimination mark 50 and the coil or connecting conductor (particularly the coil conductor, via conductor, and land in the same layer as the discrimination mark 50 in the case shown in FIG. 11B). Furthermore, the size (height dimension) of the discrimination mark 50 can be set to a size that allows it to be exposed on the first main surface 13 of the laminate 10 even if cutting misalignment occurs in the laminate block.

[0101] 12 is a perspective front view schematically showing another example of the internal structure of the laminate constituting the multilayer coil component according to the second embodiment of the present invention, illustrating a first modified example of the cutout. Fig. 12 shows the laminate as viewed from the first external electrode side (or the second external electrode side) in the axial direction of the coil.

[0102] 11B and 12, the discrimination mark 50 may have a linear cutout 51. This makes it possible to effectively increase the size of the discrimination mark 50 (lengthen in the height direction) while suppressing an increase in stray capacitance. The discrimination mark 50 may be pentagonal as shown in FIG. 11B, or quadrangular (e.g., trapezoidal) as shown in FIG. 12.

[0103] 13 is a perspective front view schematically illustrating yet another example of the internal structure of the laminate constituting the multilayer coil component according to the second embodiment of the present invention, showing a second modified example of the cutout. Fig. 13 shows the laminate as viewed from the first external electrode side (or the second external electrode side) in the axial direction of the coil.

[0104] 13, the discrimination mark 50 may have a shape in which the notch 51 follows the outer periphery of the coil conductor (preferably, each of the coil conductors 32a, 32b, 32c, and 32d) when the laminate 10 is viewed from above in the axial direction of the coil L. This also makes it possible to effectively increase the size of the discrimination mark 50 (lengthen in the height direction) while suppressing an increase in stray capacitance. In this case, the notch 51 may have a curved shape, such as an arc shape.

[0105] 11B, 12, and 13, in this embodiment, when the discrimination mark is provided at a position shifted from the axis AA perpendicular to the first main surface 13, T1 is larger than T2, where T1 is the dimension of the discrimination mark in the height direction of the laminate farther from the axis AA and T2 is the dimension closer to the axis AA. T1 corresponds to the distance from the first main surface 13 to the highest position of the conductor pattern for mark when the multilayer coil component is viewed in plan from the axial direction of the coil L with the second main surface 14 facing up and the first main surface 13 facing down. T2 corresponds to the distance from the first main surface 13 to the lowest position of the notch 51 of the conductor pattern for mark when the multilayer coil component is viewed in plan from the axial direction of the coil L with the second main surface 14 facing up and the first main surface 13 facing down. 11B, 12, and 13, when the multilayer coil component is viewed from above in the axial direction of the coil L with the second main surface 14 facing up and the first main surface 13 facing down, T1 may be greater than the distance (shortest distance) from the first main surface 13 of the coil L and the distance (shortest distance) of the first connecting conductor 41 or the second connecting conductor 42 from the first main surface 13 of the coil L, and T2 may be smaller than the distance (shortest distance) from the first main surface 13 of the coil L and the distance (shortest distance) of the first connecting conductor 41 or the second connecting conductor 42 from the first main surface 13 of the coil L. T1 may be, for example, 10 μm or less as a dimension after firing. As shown in FIGS. 11B, 12, and 13, in this embodiment as well, the shortest distance B between the coil L and the discrimination mark and the shortest distance C between the first connecting conductor 41 or the second connecting conductor 42 and the discrimination mark may each be 5 μm or more, or may be 10 μm or more. If the shortest distance B between the coil L and the discrimination mark is 5 μm or more, the increase in stray capacitance can be suppressed, resulting in good high-frequency characteristics. If the shortest distance B is 10 μm or more, the increase in stray capacitance can be further suppressed, resulting in even better high-frequency characteristics.

[0106] Here, an example of a method for manufacturing the multilayer coil component according to the second embodiment of the present invention will be described. The multilayer coil component according to this embodiment can be manufactured in the same manner as the multilayer coil component according to the first embodiment, except for the following.

[0107] In this embodiment, at least one coil sheet is a coil sheet with marks on which a conductor pattern for marks is formed.

[0108] The coil sheets and the marked coil sheets are then stacked so that after cutting, a coil having a coil axis parallel to the mounting surface is formed inside the laminate. Furthermore, via sheets on which via conductors serving as connecting conductors are formed are stacked one above the other. At least one of the via sheets is a marked via sheet on which a marking conductor pattern is formed. In this manner, the multilayer coil component according to the second embodiment of the present invention can be fabricated.

[0109] In the above embodiment, a case has been described in which a notch is provided in the conductor pattern for mark that constitutes each discrimination mark, but in the multilayer coil component of the present invention, it is sufficient that a notch is provided in at least one conductor pattern for mark, and when multiple conductor patterns for mark are provided, a notch may be provided in at least one conductor pattern for mark. However, from the viewpoint of reducing stray capacitance, it is preferable that a notch is provided in each of the conductor patterns for mark that constitutes the discrimination mark.

[0110] In the multilayer coil component of the present invention, the structure of the laminate is not limited to the structures shown in Figs. 3 and 10. For example, the shape of the coil conductor or the mark conductor pattern can be changed as desired. Furthermore, the number and order of the insulating layers 31e and 31f stacked on the outside of the coil can be changed as desired. Note that the insulating layer 31e is not essential.

[0111] When the laminated coil component of the present invention is 0603 size, the distance between the coil conductors in the stacking direction is preferably 3 μm or more and 7 μm or less. By setting the distance between the coil conductors in the stacking direction to 3 μm or more and 7 μm or less, the number of coil turns can be increased, thereby reducing the capacitance between the coil conductors and increasing the impedance. In addition, the transmission coefficient S21 in the high frequency band, which will be described later, can be reduced.

[0112] The multilayer coil component of the present invention includes the first connecting conductor and the second connecting conductor described above. Such a multilayer coil component has excellent high-frequency characteristics in the high-frequency band (particularly, 30 GHz or higher and 80 GHz or lower). Therefore, it can be suitably used, for example, in a bias-tee circuit in an optical communication circuit.

[0113] In the multilayer coil component of the present invention, the transmission coefficient S21 at 40 GHz is evaluated as the high-frequency characteristic. The transmission coefficient S21 is calculated from the ratio of the power of the transmitted signal to the power of the input signal. The transmission coefficient S21 is basically a dimensionless quantity, but is usually expressed in dB units using a common logarithm.

[0114] In the multilayer coil component of the present invention, the transmission coefficient S21 at 40 GHz is preferably 0 dB or less and −1.0 dB or more.

[0115] The present specification discloses the following:

[0116] <1> a laminate formed by laminating a plurality of insulating layers and having a coil, a first connecting conductor, and a second connecting conductor therein; a first external electrode and a second external electrode electrically connected to the coil; the coil is formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, the laminate has a first end face and a second end face opposing each other in a length direction, a first main face and a second main face opposing each other in a height direction perpendicular to the length direction, and a first side face and a second side face opposing each other in a width direction perpendicular to the length direction and the height direction, the first external electrode is disposed so as to cover at least a portion of the first end face and extend from the first end face to cover a portion of the first main surface; the second external electrode is disposed so as to cover at least a portion of the second end face and extend from the second end face to cover a portion of the first main surface; the first connecting conductor connects the first external electrode in a portion covering the first end face to the coil conductor facing the first external electrode; the second connecting conductor connects the second external electrode in a portion covering the second end face to the coil conductor facing the second external electrode, the axial direction of the coil is parallel to the first principal surface, a first discrimination mark is provided on a surface of the laminate excluding the first end face and the second end face, at a location where the first external electrode is to be disposed; the first discrimination mark includes a first mark conductor pattern that is in contact with an inner surface of the first external electrode and has a surface extending in a direction perpendicular to the axial direction of the coil, The first mark conductor pattern has a notch formed in a position facing the coil axis of the coil.

[0117] <2> the first discrimination mark includes two or more conductive patterns for the first mark that are provided at a distance from each other; <1> The multilayer coil component according to claim 1.

[0118] <3> the first discrimination mark includes the first mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis, the cross section including the first connecting conductor; <1> or <2> The multilayer coil component according to claim 1.

[0119] <4> the first mark conductor pattern formed on the cross section where the first connecting conductor is formed has a shape in which the notch follows an outer periphery of the first connecting conductor when the laminate is viewed in a plan view in the axial direction of the coil. <3> The multilayer coil component according to claim 1.

[0120] <5> the first discrimination mark includes the first mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis, where the first connecting conductor is formed, and the first mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis, where the coil conductor is formed. <3> or <4> The multilayer coil component according to claim 1.

[0121] <6> the first discrimination mark includes the first mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis, in which the coil conductor is formed; <1> from <5> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0122] <7> the first mark conductor pattern formed on the cross section where the coil conductor is formed has a shape in which the notch follows the outer periphery of the coil conductor when the laminate is viewed in a plan view in the axial direction of the coil. <6> The multilayer coil component according to claim 1.

[0123] <8> the first discrimination mark includes a conductive pattern for the first mark, the notch of which is linear; <1> from <7> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0124] <9> the first discrimination mark includes the first mark conductor patterns provided at two locations symmetrically with respect to an axis perpendicular to the first main surface when viewed in a plan view from the axial direction of the coil, the first discrimination mark including the first mark conductor patterns provided at two locations symmetrically with respect to an axis perpendicular to the first main surface and spaced apart from each other; <1> from <8> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0125] <10> The first discrimination mark is composed of only the first mark conductive pattern whose shortest distance to the coil is 5 μm or more, or the first mark conductive pattern whose shortest distance to the first connecting conductor is 5 μm or more, or only both of them. <1> from <9> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0126] <11> The first discrimination mark is composed of only the first mark conductive pattern whose shortest distance to the coil is 10 μm or more, or the first mark conductive pattern whose shortest distance to the first connecting conductor is 10 μm or more, or only both of them. <1> from <10> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0127] <12> when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second main surface facing up and the first main surface facing down, a distance from the first main surface to a highest position of the first mark conductor pattern is greater than a distance from the first main surface to the coil and a distance from the first main surface to the first connecting conductor. <1> from <11> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0128] <13> when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second main surface facing up and the first main surface facing down, a distance from the first main surface to a lowest position of the notch of the first mark conductor pattern is smaller than a distance from the first main surface of the coil and a distance from the first main surface of the first connecting conductor. <1> from <12> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0129] <14> a second discrimination mark is provided on a surface of the laminate excluding the first end face and the second end face, at a location where the second external electrode is to be disposed; the second discrimination mark includes a second mark conductor pattern that is in contact with the inner surface of the second external electrode and has a surface extending perpendicular to the axial direction of the coil, the second mark conductor pattern has a notch formed in a position facing the coil axis; <1> from <13> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0130] <15> the second discrimination mark includes two or more second mark conductive patterns provided at a distance from each other; <14> The multilayer coil component according to claim 1.

[0131] <16> the second discrimination mark includes the second mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis, the cross section including the second connecting conductor; <14> or <15> The coil component according to claim 1.

[0132] <17> the second mark conductor pattern formed on the cross section where the second connecting conductor is formed has a shape in which the notch follows an outer periphery of the second connecting conductor when the laminate is viewed in a plan view in the axial direction of the coil. <16> The multilayer coil component according to claim 1.

[0133] <18> the second discrimination mark includes the second mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis where the second connecting conductor is formed, and the second mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis where the coil conductor is formed. <16> or <17> The multilayer coil component according to claim 1.

[0134] <19> the second discrimination mark includes the second mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis, in which the coil conductor is formed. <14> from <18> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0135] <20> the second mark conductor pattern formed on the cross section where the coil conductor is formed has a shape in which the notch follows the outer periphery of the coil conductor when the laminate is viewed in a plan view in the axial direction of the coil. <19> The multilayer coil component according to claim 1.

[0136] <21> the second discrimination mark includes a conductive pattern for the second mark, the notch of which is linear; <14> from <20> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0137] <22> the second discrimination mark includes the second mark conductor patterns provided at two locations symmetrically with respect to an axis perpendicular to the first principal surface when viewed in a plan view from the axial direction of the coil, and <14> from <21> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0138] <23> the second discrimination mark is composed of only the second mark conductive pattern whose shortest distance to the coil is 5 μm or more, or the second mark conductive pattern whose shortest distance to the second connecting conductor is 5 μm or more, or is composed of only both of them; <14> from <22> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0139] <24> The second discrimination mark is composed of only the second mark conductive pattern whose shortest distance to the coil is 10 μm or more, or the second mark conductive pattern whose shortest distance to the second connecting conductor is 10 μm or more, or only both of them. <14> from <23> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0140] <25> when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second principal surface facing up and the first principal surface facing down, a distance from the first principal surface to a highest position of the second mark conductor pattern is greater than a distance from the first principal surface of the coil and a distance from the first principal surface of the second connecting conductor. <14> from <24> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated.

[0141] <26> when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second main surface facing up and the first main surface facing down, a distance from the first main surface to a lowest position of the notch of the second mark conductor pattern is smaller than a distance from the first main surface of the coil and a distance from the first main surface of the second connecting conductor. <14> from <25> 10. The multilayer coil component according to claim 9, wherein the first and second layers are laminated. [Explanation of symbols]

[0142] 1.1A multilayer coil components 10,10A laminate 11 first end face 12 Second end face 13 First principal surface 14 Second main surface 15 First Aspect 16 The Second Aspect 21 First external electrode 22 second external electrode 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h, 31j, 31k Insulating layer 32a, 32b, 32c, 32d Coil conductors 33a, 33b, 33c, 33d, 33e, 33f via conductors 34 Mark conductor pattern 35a, 35b, 35c, 35d, 35f Land 41 First connecting conductor 42 Second connecting conductor 50 Discrimination Mark 51 Notch L coil A Coil axis of coil AA Axis perpendicular to the first principal plane

Claims

1. a laminate formed by laminating a plurality of insulating layers and having a coil, a first connecting conductor, and a second connecting conductor therein; a first external electrode and a second external electrode electrically connected to the coil; the coil is formed by electrically connecting a plurality of coil conductors stacked together with the insulating layer, the laminate has a first end face and a second end face opposing each other in a length direction, a first main surface and a second main surface opposing each other in a height direction perpendicular to the length direction, and a first side surface and a second side surface opposing each other in a width direction perpendicular to the length direction and the height direction, the first external electrode is disposed so as to cover at least a portion of the first end face and extend from the first end face to cover a portion of the first main surface; the second external electrode is disposed so as to cover at least a portion of the second end face and extend from the second end face to cover a portion of the first main surface; the first connecting conductor connects the first external electrode in a portion covering the first end face to the coil conductor facing the first external electrode; the second connecting conductor connects the second external electrode in a portion covering the second end face to the coil conductor facing the second external electrode, the axial direction of the coil is parallel to the first principal surface, the first connecting conductor and the second connecting conductor extend along a coil axis of the coil; the first external electrode and the second external electrode are respectively disposed on the first end surface and the second end surface where a coil axis of the coil intersects, and on the first main surface adjacent thereto; a first discrimination mark is provided on a surface of the laminate excluding the first end face and the second end face, at a location where the first external electrode is to be disposed; the first discrimination mark includes a first mark conductor pattern that is in contact with an inner surface of the first external electrode and has a surface extending in a direction perpendicular to the axial direction of the coil, The first mark conductor pattern has a notch formed in a location facing the coil axis of the coil.

2. 2. The multilayer coil component according to claim 1, wherein the first discrimination mark includes two or more first mark conductor patterns provided at a distance from each other.

3. 3. The multilayer coil component according to claim 1, wherein the first discrimination mark includes the first mark conductor pattern formed on a cross section of the laminate perpendicular to the coil axis, the cross section including the first connecting conductor.

4. 4. The multilayer coil component according to claim 3, wherein the first mark conductor pattern formed on the cross section where the first connecting conductor is formed has a shape in which the notch follows an outer periphery of the first connecting conductor when the laminate is viewed in a plane in the axial direction of the coil.

5. 4. The laminated coil component according to claim 3, wherein the first discrimination mark includes the first mark conductor pattern formed on a cross section of the laminate perpendicular to the coil axis where the first linking conductor is formed, and the first mark conductor pattern formed on a cross section of the laminate perpendicular to the coil axis where the coil conductor is formed.

6. 3. The multilayer coil component according to claim 1, wherein the first discrimination mark includes a conductor pattern for the first mark formed on a cross section of the laminate perpendicular to the coil axis, the cross section including the coil conductor.

7. 7. The multilayer coil component according to claim 6, wherein the first mark conductor pattern formed on the cross section where the coil conductor is formed has a shape in which the cutout follows an outer periphery of the coil conductor when the laminate is viewed in a plan view in the axial direction of the coil.

8. 3. The multilayer coil component according to claim 1, wherein the first discrimination mark includes a conductor pattern for the first mark, the notch of which is linear.

9. 3. The multilayer coil component according to claim 1, wherein the first discrimination mark includes the first mark conductor patterns provided at two locations symmetrically with respect to an axis perpendicular to the first main surface and spaced apart from each other when viewed in a plan view from the axial direction of the coil.

10. 3. The multilayer coil component according to claim 1, wherein the first discrimination mark is formed solely of the first mark conductor pattern whose shortest distance to the coil is 5 μm or more, or the first mark conductor pattern whose shortest distance to the first connecting conductor is 5 μm or more, or both.

11. 3. The multilayer coil component according to claim 1, wherein the first discrimination mark is formed solely of the first mark conductor pattern whose shortest distance to the coil is 10 μm or more, or the first mark conductor pattern whose shortest distance to the first connecting conductor is 10 μm or more, or both.

12. 3. The multilayer coil component according to claim 1, wherein, when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second main surface facing up and the first main surface facing down, a distance from the first main surface to a highest position of the first mark conductor pattern is larger than a distance from the first main surface of the coil and a distance from the first main surface of the first connecting conductor.

13. 3. The multilayer coil component according to claim 1, wherein, when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second main surface facing up and the first main surface facing down, a distance from the first main surface to a lowest position of the notch of the first mark conductor pattern is smaller than a distance from the first main surface of the coil and a distance from the first main surface of the first connecting conductor.

14. a second discrimination mark is provided on a surface of the laminate excluding the first end face and the second end face, at a location where the second external electrode is to be disposed; the second discrimination mark includes a second mark conductor pattern that is in contact with an inner surface of the second external electrode and has a surface extending perpendicular to the axial direction of the coil, 3. The multilayer coil component according to claim 1, wherein the second mark conductor pattern has a notch formed in a location facing the coil axis.

15. 15. The multilayer coil component according to claim 14, wherein the second discrimination mark includes two or more second mark conductor patterns provided at a distance from each other.

16. 15. The multilayer coil component according to claim 14, wherein the second discrimination mark includes the second mark conductor pattern formed in a cross section of the laminate perpendicular to the coil axis, the cross section including the second connecting conductor.

17. 17. The multilayer coil component according to claim 16, wherein the second mark conductor pattern formed on the cross section where the second connecting conductor is formed has a shape such that the cutout follows an outer periphery of the second connecting conductor when the laminate is viewed in a plane in the axial direction of the coil.

18. 17. The laminated coil component according to claim 16, wherein the second discrimination mark includes the second mark conductor pattern formed on a cross section of the laminate orthogonal to the coil axis, the cross section including the second linking conductor, and the second mark conductor pattern formed on a cross section of the laminate orthogonal to the coil axis, the cross section including the coil conductor.

19. 15. The multilayer coil component according to claim 14, wherein the second discrimination mark includes a conductor pattern for the second mark formed in a cross section of the laminate perpendicular to the coil axis, the cross section including the coil conductor.

20. 20. The multilayer coil component according to claim 19, wherein the second mark conductor pattern formed on the cross section where the coil conductor is formed has a shape in which the cutout follows an outer periphery of the coil conductor when the laminate is viewed in a plan view in the axial direction of the coil.

21. 15. The multilayer coil component according to claim 14, wherein the second discrimination mark includes a second mark conductor pattern in which the notch is linear.

22. 15. The multilayer coil component according to claim 14, wherein the second discrimination mark includes the second mark conductor patterns provided at two locations symmetrically with respect to an axis perpendicular to the first main surface and spaced apart from each other when viewed in a plan view from the axial direction of the coil.

23. 15. The multilayer coil component according to claim 14, wherein the second discrimination mark is formed solely of the second mark conductor pattern whose shortest distance to the coil is 5 μm or more, or the second mark conductor pattern whose shortest distance to the second connecting conductor is 5 μm or more, or both.

24. 15. The multilayer coil component according to claim 14, wherein the second discrimination mark is formed solely of the second mark conductor pattern whose shortest distance to the coil is 10 μm or more, or the second mark conductor pattern whose shortest distance to the second connecting conductor is 10 μm or more, or both.

25. 15. The multilayer coil component according to claim 14, wherein, when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second main surface facing up and the first main surface facing down, a distance from the first main surface to a highest position of the second mark conductor pattern is larger than a distance from the first main surface of the coil and a distance from the first main surface of the second connecting conductor.

26. 15. The multilayer coil component according to claim 14, wherein, when the multilayer coil component is viewed in a plan view from the axial direction of the coil with the second main surface facing up and the first main surface facing down, a distance from the first main surface to a lowest position of the notch of the second mark conductor pattern is smaller than a distance from the first main surface of the coil and a distance from the first main surface of the second connecting conductor.

Images